Unilateral vocal fold paralysis (UVFP) is caused by injury to the recurrent laryngeal nerve. Patients with UVFP may have significant impairment of vocal cord function, including a breathy paralytic dysphonia. There are several available approaches for the treatment of this condition. Vocal fold medialization is currently used by most otolaryngologists and is probably the standard of care for treating this condition. An alternative approach is laryngeal reinnervation, which has a number of potential advantages over medialization but which requires several months before a final result is achieved. The primary goal of this study is to determine which approach produces a better outcome, i.e. to determine whether the theoretical advantages of reinnervation are actually achieved, and whether they outweigh the disadvantage of having to wait for them. Previous studies comparing these approaches have been small and limited by significant non-randomized patient selection bias. The study design is a multicenter, prospective, randomized clinical trial. Patients with UVFP meeting all inclusion criteria and released from therapy by a speech-language pathologist will be invited to participate. Participants will be stratified by site of lesion, electromyographic findings and pretreatment voice severity, then randomized into either a medialization arm or a reinnervation arm. Patients will be recruited from 12 academic medical centers with participating surgeons; 149 patients are planned for each study arm. An intense data collection protocol including voice recordings, aerodynamic measurements, electroglottography, videolaryngostroboscopy, and a validated clinical outcomes instrument will be collected pre-treatment and at 6 and 12 months post-treatment. Subjective perceptual scores will be obtained by presenting pre- and postoperative voice samples to both naive and experienced listeners using a custom computerized algorithm. The objective measurements will undergo multivariate analysis with stepwise multiple regression. These data will be used to test the hypothesis that reinnervation gives better results than medialization in patients with UVFP.